Type wheel indexing mechanism in high speed printing and counting devices



March 2, 1965 H. WETZER 3,171,348

TYPE W L I XING MECHANISM IN HIGH SPEED INT N AND COUNTING DEVICES Filed June 27, 1960 INVENTOR HERMAN WETZER Attorneys United States Patent 3,171,348 TYPE WHEEL EJDEXWG MECHANEM llN HHGH SPEED PRlN'lilNG AND (IUUNTHNG BEVHIES Hermann Wetzer, Pfronten-Meilingen, Germany Filed June 27, 60, Ser. No. 39,044 Claims priority, application Germany, fay 3t), 1960, W 27,941 2 Claims. (3. lull-93) The invention relates to a locking device for counting and printing mechanism employing rapidly succeeding electric current driver pulses.

It is an object of the invention to ensure that the print and counting mechanism of the type referred to operates reliably during rapid counting sequences.

According to my copending application (Ser. No. 794,- 932 filed July 19, 1958, now US. Patent No. 3,103,878) the counting and printing mechanism for rapidly succeeding current pulses is comprised of a selector magnet which is adapted to rotate a type wheel via intermediate elements and a step mechanism, the printing being effected by means of a printing mechanism arranged below the type wheel and paper.

This arrangement still has a disadvantage in that with the rapid sequence and rapid movement of the step mechanism the type wheel is not arrested in each position i.e. it is possible for it to move in reverse direction when it should move forwardly. The step m chanism which is adapted to constantly carry out half steps during attraction as well as during a release by the selector magnet, has constantly to engage the switching wheel, thus constantly ensuring a forward movement of the switching wheel.

It is a further object of the present invention to arrest a switching and/or type wheel with respect to reverse movement, so that said wheels may only execute a forward rotation. The problem is solved in accordance with the invention in providing a ball type locking device between a fixed dog and a running surface of a type wheel, so that during, for example, the attraction of the armature operating the type wheel, the reverse movement thereof is locked.

It is believed apparent that, in a general way, a stepwise movement of a type wheel also constitutes a counting, which may or may not be succeeding by a printing step; therefore, as to be used hereinafter, counting also is understood to embrace the possibility of a later printing.

An example of the invention is shown in the drawing,

further features of the invention becoming evident from 5 the drawing and the description thereof.

16. 1 is a front elevation of an arrangement of type wheel-contact wheels-switching wheel with a ball catch partly exposed;

FIG. 2 is a side view corresponding to FIG. 1 in longitudinal section.

In the drawing the same reference numerals denote the same parts as in applicants copending application, Ser. No. 794,982, filed July 19, 1953. Thus, the type wheel 14 is assembled with contact wheels 15, i6 and a switching wheel 17 to form an integral unit and, when the switching wheel 17 is advanced electromagnetically and in steps, the wheels connected therewith are moved accordingly. The movement of the wheels is effected just as in the copending application by means of the step mechanism and/ or the selector magnets when the corresponding current impulses are provided type wheel M has a recess receiving an annular member 57 provided with an inner annular running surface 54 coaxially with wheels 14 to 17. There is provided a stationary dog 53 latented Mar. 2, i965 "ice having a wedge-shaped recess with a tangentially extending surface and a substantially extending surface 52. A

ball 5t? and a spring 51 is interposed between recess surface 52 and the wedge formed by surface 52, and a position of surface 54.

If the type wheel moves in the direction of the arrow 55, then the ball 59 due to adhesive friction is urged against the spring 51 and the wedge-shaped recess 52 formed in the dog 53 is rendered ineffective. If due to any engagement position of the step mechanism the switching wheel 17 and the type wheel 14 is moved in the direction of the arrow 56, then this direction of movement is immediately blocked, because the ball is urged into the wedge-shaped notch or recess 52 by means of the spring 51 and caused to lock this movement immediately.

Of course, it is possible by suitable means to render the lock as described ineffective, e.g. by means of a magnetically actuated ram which urges the ball 5%) against the spring 51 and permits the type wheel 14 then to be rotated in the direction of the arrow 56. The dog 53 may also be formed as a rotatable disc which normally is arrested by means of a locking pin and, when this lock is released, the dog 53 no longer acts as a lock when the type wheel 14 is moved in the direction of the arrow 56. This case may arise when it is required to transfer from forward counting in the direction of the arrow to counting in reverse in the direction of the arrow 56. Other possibilities for locking are given by providing a lateral frictionor locking washer.

As a field of application of the invention is considered, all the possibilities in which it is intended to exclude an undesired direction of a rotary movement of the type wheel 14 without using type ratchet locks. The ball type locking device as described may, alternatively, be accom modated in the switching wheel 17 or in any of the contact wheels 15, 16. It is also possible to have the running surface 54 provided as a rough or knurled surface, in order to increase the locking efiect when the ball 50 is wedged between this surface 54 and recess 52.

I claim:

1. In a high speed electromagnetically operated count ing apparatus, the combination comprising: an electromagnetically stepwise rotated switching Wheel; a type wheel secured to said switching wheel defining a unitary structure therewith, said unitary structure including means defining a circular recess, said recess having an annular surface coaxial with said wheels; a stationary member received by said recess; said member having a wedge-shaped recess, with a substantially tangentially, and a substantially radially extending surface, and a ball and spring arrangement, disposed in said wedge-shaped recess so that said ball engages said annular surface and said spring engages said ball and said radially extending surface.

2. In a high speed electromagnetically operated counting apparatus comprising: an electromagnetically stepwise rotated switching wheel; a type wheel secured to said switching wheel for common rotation, said type wheel having a circular recess with an annular surface coaxial with said wheels; a stationary member received by said recess, said member having a wedge-shaped recess with a substantially tangentially directed surface and a substantially radially directed surface; and a ball and spring arrangement disposed in said wedge-shaped recess, so that said ball engages said annular surface and said tangential surface, while said spring engages said radial surface.

(References on foilowing page) References Cited in the file of this patent UNITED STATES PATENTS Anibal Sept. 16, 1924 Meyer Jan. 21, 1932 5 Dechene Mar. 21, 1933 4 Harrison Sept. 19, 1933 Tyler et a1 July 24, 1934 Dennis et a1 Nov. 7, 1939 Ross Oct. 8, 1940 Pekar et a1. July 7, 1959 Cignetti Nov. 3, 1959 

1. IN A HIGH SPEED ELECTROMAGNETICALLY OPERATED COUNTING APPARATUS, THE COMBINATION COMPRISING: AN ELECTROMAGNETICALLY STEPWISE ROTATED SWITCHING WHEEL; A TYPE WHEEL SECURED TO SAID SWITCHING WHEEL DEFINING A UNITARY STRUCTURE THEREWITH, SAID UNITARY STRUCTURE INCLUDING MEANS DEFINING A CIRCULAR RECESS, SAID RECESS HAVING AN ANNULAR SURFACE COAXIAL WITH SAID WHEELS; A STATIONARY MEMBER RECEIVED BY SAID RECESS; SAID MEMBER HAVING A WEDGE-SHAPED RECESS, WITH A SUBSTANTIALLY TANGENTIALLY, AND A SUBSTANTIALLY RADIALLY EXTENDING SURFACE, AND A BALL AND SPRING ARRANGEMENT, DISPOSED IN SAID WEDGE-SHAPED RECESS SO THAT SAID BALL ENGAGES SAID ANNULAR SURFACE AND SAID SPRING ENGAGES SAID BALL AND SAID RADIALLY EXTENDING SURFACE. 